Various rsync deployment fixups:

1) If ssh_key was absent, you'd get an error.
2) Had to specify full path to key ("/Users/jfrisby/.ssh/...") -- couldn't use "~/.ssh/...".  Since SSH demands it be there anyway, let's pre-populate for the user and make their lives easier.
3) Ensure uniform and consistent trailing slashes on source and dest paths to avoid accidentally mucking things up.